This invention relates to a tape recording-reproducing apparatus.
The magnetic tape used in magnetic recording-reproducing apparatus such as a video tape apparatus and an audio tape apparatus consists of a plastic film and a magnetic coating laid on the film. The magnetic tape, or more precisely its magnetic coating, may easily be electrified or charged. The tape, when electrified, will attract dust or will likely be attracted to a thing placed near it. If this happens, the tape is prevented from running as smoothly as desired. Dust, if stuck on the tape, will cause discharge noise which deteriorates the quality of the image or sound reproduced. The tape, if attracted to a thing, cannot be so smoothly taken up as to form a reel having smooth sides.
To avoid such an unwanted electrification, carbon black or graphite is coated on the plastic film of a magnetic tape or mixed with a binder in the magnetic coating, thereby to reduce the electric resistance of the magnetic coating. This, however, cannot fully prevent charging of electrification of a magnetic tape.